JP3156969B2 - Polybutene moldings - Google Patents

Description

The present invention relates to a molded article of polybutene-1. More specifically, the present invention relates to a molded product of polybutene-1 having a specific crystal structure.

(Prior art)

Isotactic polybutene-1 has been known for some time, and its use for various uses has been studied. However, polybutene-1 having a syndiotactic structure has not been known.

[Problems to be solved by the invention]

Polypropylene with a high syndiotacticity was first discovered by JAEWEN et al. (J.Am.C.
hem. Soc., 1988, 110, 6255-6256) can be produced by using a catalyst comprising a transition metal compound having an asymmetric ligand and aluminoxane. Butene-1 sufficiently purified using this catalyst is used. It has been found by us that the polymerization of polybutene-1 gives very high syndiotacticity. (Japanese Patent Application No. 1-141168) However, the crystallinity of this product has not been fully understood.

[Means for solving the problem]

Means for Solving the Problems The present inventors diligently searched for crystallized polybutene-1, and found that crystalline polybutene-1 having a specific structure can be produced, and completed the present invention.

That is, the present invention provides an orthorhombic polybutene having lattice constants a = 16.9, b = 6.05, and c = 7.78 ° determined by X-ray diffraction obtained by molding polybutene-1 having a syndiotactic structure. 1 is a molded article.

The present invention will be further described by showing an example of the manufacturing method. The polybutene-1 having a highly stereoregular syndiotactic structure which can be synthesized by a method described later is melt-molded, or is dissolved in a hydrocarbon solvent such as toluene and cast to form a solvent. A molded product of polybutene-1 having two crystal structures can be obtained. The melt-formed product can be crystallized by holding it at a relatively low temperature for a relatively long time.

Syndiotactic polybutene-1 used here is:
For example, it can be produced by polymerizing butene-1 using a catalyst comprising an aluminoxane and a transition metal compound having an asymmetric ligand first discovered by JAEWEN et al. Here, preferably, the transition metal compound having an asymmetric ligand has a high purity (an inactive impurity such as lithium chloride does not cause any problem, but a transition metal compound having a structure in which one ligand is removed is particularly preferable. Less is required.)
It is preferable to use a polymer having a syndiotactic pentad fraction (Macromolecules 1983 vol16 786-7).
Polybutene-1 having good tacticity such that 90) is 0.5 or more, particularly preferably 0.7 or more, is preferably used.

Examples of the transition metal compound having an asymmetric ligand include isopropyl (cyclopentadienyl-1-fluorenyl) hafnium dichloride or isopropyl (cyclopentadienyl-1-fluorenyl) zirconium dichloride described in the above literature. , And as the aluminoxane, a general formula: (Wherein R is a hydrocarbon residue having 1 to 3 carbon atoms). In particular, methylaluminoxane wherein R is a methyl group and n is 5 or more, preferably 10 or more is used. You. The use ratio of the aluminoxane to the transition metal compound is 10 to 100,000,000 mole times, usually 50 to 5000.
It is molar times. The polymerization conditions are not particularly limited, and a solvent polymerization method using an inert medium, a bulk polymerization method substantially free of an inert medium, and a gas phase polymerization method can be used. In general, the polymerization is carried out at a temperature of -100 to 200 ° C. and at a pressure of normal pressure to 100 kg / cm ² . Preferably, it is -100 to 100 ° C and normal pressure to 50 kg / cm ² .

When the above catalyst is used, a polymer having a narrow molecular weight distribution by performing substantially one-stage polymerization during polymerization and having a ratio of the weight average molecular weight to the number average molecular weight measured by gel permeation chromatography at 135 ° C. which is usually about 1.5 to 3.5. However, it is effective to use two kinds of transition metal compounds (for example, it is effective to use two kinds of metals such as zirconium and hafnium) or to use two kinds of compounds having different molecular weights.
Those having a wide molecular weight distribution of 3.5 or more can be produced by mixing more than one kind, and those having any molecular weight distribution can be used in the present invention. The preferred molecular weight is generally about 0.5 to 20.0 dl / g as the intrinsic viscosity measured with a 135 ° C. tetralin solution.

The polybutene-1 having a syndiotactic structure obtained by the above method is heated and melted to form a specific shape as described above, or dissolved in a hydrocarbon solvent having 5 to 20 carbon atoms, and then cast and formed. A molded product is obtained by removing the solvent by evaporation. The molded product, particularly a melt-molded product, can be converted into crystalline polybutene-1 by holding it at a relatively low temperature after molding, preferably at 40 ° C. or lower for a relatively long time. In order to obtain polybutene-1 having this crystal structure, polybutene-1 having a highly syndiotactic structure is used.
It is necessary to maintain the temperature at a low temperature for a relatively long time, for example, several hours to several days by using No. 1.

FIG. 1 shows a photograph of an X-ray diffraction image of the molded product thus produced having substantially one crystal structure, taken with a Weissenberg camera, using Cu-Kα radiation. The lattice constants determined from the X-ray diffraction measurement results are a = 16.9, b = 6.05, c =
It is an orthorhombic crystal with 7.78%, and one period is composed of 8 monomer units.

〔Example〕

 Hereinafter, the present invention will be described with reference to Examples.

Example 1 5 mg of isopropyl (cyclopentadienyl-1-fluorenyl) zirconium dichloride obtained by lithiation of isopropylcyclopentadienyl-1-fluorene synthesized according to a conventional method, reaction with zirconium tetrachloride, and recrystallization were obtained. Using 0.34 g of methylaluminoxane manufactured by Toyo Akzo Co., Ltd. (degree of polymerization 16.1), 40 g of butene-1 was stirred and mixed at 25 ° C for 5 hours in an autoclave having an internal volume of 200 mml. After the reaction, unreacted butene-1 was removed by evaporation, and 100 ml of hexane was added to the remaining solid matter, and 50 ml of ketanol was further added.
The mixture was treated at 60 ° C. for 30 minutes, and the hexane solution was further washed with water. The hexane solution was concentrated to about 30 ml, and then cast to obtain a sheet. Sheet 30 at 30 ℃
After drying for an hour, hexane was completely removed. A part of this molded product was dissolved, the syndiotactic pentad fraction measured by ¹³ C-NMR was 0.92, and the molecular weight in terms of propylene measured by gel permeation chromatography was 27500, which was a number average molecular weight. The molecular weight was 42,500. An X-ray fiber photograph of the obtained sheet is shown in FIG. From this result, the lattice constants are a = 16.9, b = 6.05, c = 7.78Å
Is an orthorhombic crystal which is 1 unit in 8 monomer units.
It can be seen that it constitutes a period.

〔The invention's effect〕

The molded article of the present invention is crystalline at room temperature and can be expected to have various uses.

[Brief description of the drawings]

FIG. 1 is a photograph of the result of measurement of X-ray diffraction of a molded product of polybutene-1 of the present invention instead of the drawing.

Claims (1)

(57) [Claims] An orthorhombic polybutene having lattice constants a = 16.9, b = 6.05 and c = 0.78 ° determined by X-ray diffraction obtained by molding polybutene-1 having a syndiotactic structure. 1 molded article.